This invention relates generally to conversion of solar energy to usable energy. More specifically, it concerns highly efficient solar collector apparatus characterized as heating throughput liquid to very high comparative temperatures.
In the past, low cost solar collectors were undesirably limited in their abilities to heat throughput liquids to desired temperatures. For example, simple flat plate collectors could not operate efficiently to produce throughput liquid temperatures approaching 100.degree. C. Also, flat plate collectors have relatively low efficiency because they conduct, convect and radiate through the cover plate to a temperature determined by ambient. Accordingly, there is a need for simple means to enable low cost collectors to operate at much higher temperatures, and higher efficiencies.